Julian Assange has sought refuge in the Ecuadorean embassy since 2012 to avoid extradition to swedenReuters

Sweden's head prosecutor, Marianne Ny has asked to question WikiLeaks founder Julian Assange in London over allegations that he sexually assaulted two women in Sweden in 2010. Ny has also asked to have Assange's DNA taken via a swab, according to the Swedish Prosecution Authority.

Assange has been holed up in the Ecuadorian Embassy in London since June 2012 to avoid being sent to Sweden to face the claims. The Australian national fears if Britain forces him to go to Sweden, he will be handed over to US authorities to face charges for leaking thousands of classified documents.

Assange denies all the sexual assault allegations against him. He has previously called on Swedish prosecutors to question him in London, either in person or via videolink. The Foreign Office said it would welcome this possibly, but prosecutors in Stockholm have argued against it as it is not normal practice.

One of Assange's lawyers, Per Samuelson, has welcomed the offer. "This is something we've demanded for over four years," he said.

"Julian Assange wants to be interviewed so he can be exonerated."

Ny said in a statement: "My view has always been that to perform an interview with him at the Ecuadorean embassy in London would lower the quality of the interview, and that he would need to be present in Sweden in any case should there be a trial in the future.

"Now that time is of the essence, I have viewed it therefore necessary to accept such deficiencies in the investigation and likewise take the risk that the interview does not move the case forward."